digitalmars.D.learn - class templates and static if

So, here's my code, as it stands currently:
import std.stdio;
static enum Type {
request,
response
};
class Parser(Type t) {
static if (t == Type.request) {
string name = "request";
} else {
string name = "response";
}
string message;
this(string message) {
this.message = message;
}
}
void main() {
immutable Type t = Type.request;
Parser!t h = new Parser!t("Hello world");
writefln("%s: %s", h.name, h.message);
}
The general goal is to make a templated class that will only include the
parts that each needs. I would like to keep this all as one class template,
because there is a lot of shared code, and I would like to keep it as
seamless as possible and not have to separate out code into separate
functions.
Anyway, my current approach is a little clunky, because it requires an
immutable to be created just to tell the compiler what type of parser I
need.
I was thinking about having two classes, Request and Response, and have
parser take a normal template (class Parser (T)), but I wanted to restrict
it to just those two classes (for now), so I came up with the enum solution.
Is there a better way to do this?
What I'd ultimately like to do is have some static if surrounding blocks of
code that depends on the input to the template.